1. Field of the Invention
The present invention relates to a seat structure having an air bag apparatus for a side impact (hereinafter referred to as a xe2x80x9cside impact air bag apparatusxe2x80x9d), and more particularly to a seat structure which has aside impact air bag apparatus at a side portion of a seat back frame.
2. Description of the Related Art
A seat structure having a side impact air bag apparatus has been conventionally known, and Japanese Patent Application Laid-Open (JP-A) No. 4-50052, U.S. Pat. No. 5,348,342, U.S. Pat. No. 5,112,079, U.S. Pat. No. 5,222,761, U.S. Pat. No. 5,251,931, U.S. Pat. No. 5,498,030, etc., disclose such a seat structure. Among them, Japanese Patent Application Laid-Open (JP-A) No. 4-50052 discloses a seat structure in which a folded air bag is accommodated in a concave portion formed in a side portion of a seat base member. FIGS. 7 and 8 show an example of such a seat structure having a side impact air bag apparatus.
In the seat structure shown in FIG. 7, an air bag apparatus 74 is disposed within a side portion 72A of a seat back 72.
As shown in FIG. 8, the air bag apparatus 74 has a box-like shape whose longitudinal direction coincides with the vertical direction of the vehicle, and is attached to a side frame (i.e., reinforcing member) 80 of a seat back frame 78 using screws 83.
As shown in FIG. 7, a lid portion 82A is disposed opposite to the side frame 80 with respect to an air bag case 82. When the air bag 84 is expanded, the lid portion 82A opens outward in the widthwise direction of the seat (in the direction of arrow W in FIG. 7) around a hinge portion 82B formed at the rear end in the longitudinal direction of the vehicle. Moreover, upon opening of the lid portion 82A, a seat surface layer 86 is ruptured.
However, the above-described seat structure having a side impact air bag apparatus has the following problems.
(1) Since the air bag apparatus 74 is attached to the outer side surface 80A of the side frame 80 in the transverse direction of the vehicle, the overall width of the seat back 72 increases.
(2) Since the air bag apparatus 74 projects from the side frame 80 further toward the rear of the vehicle than the seat back, the thickness of the side portion 72A of the seat back 72 in the longitudinal direction of the vehicle also increases.
Accordingly, the effective space within the vehicle decreases.
The present invention has been accomplished in view of the above-mentioned problems, and an object of the present invention is to provide a seat structure having a side impact air bag apparatus which can increase the space within the vehicle.
A first aspect of the present invention is a seat structure having a side impact air bag apparatus. The seat structure includes a seat back frame which has side frames each provided at a corresponding widthwise direction side of a seat. An air bag accommodating concave portion is formed in one of the side frames which opposes a vehicle door such that the concave portion extends inward from an end portion of the seat back frame in the widthwise direction of the seat. The air bag accommodating concave portion accommodates an inflator and a folded air bag. A seat pad is provided for covering the seat back frame, and a seat surface layer is provided for covering the seat pad. The seat surface layer covers the air bag accommodating concave portion and the seat pad.
In the seat structure having a side impact air bag apparatus according to the first aspect of the present invention, the inflator and the folded air bag are accommodated in the air bag accommodating concave portion, which is formed by depressing the side frame toward the inside of the seat, and the inflator and the air bag are covered by the seat surface layer together with the seat pad. Accordingly, both the overall width of the seat back and the thickness of the side portion of the seat back in the longitudinal direction of the vehicle can be decreased, and therefore the interior room space of the vehicle can be increased. Moreover, since a bracket for attachment of the air bag apparatus and an air bag case can be omitted, the assembly can be performed with improved workability.
A second aspect of the present invention is a seat structure having a side impact air bag apparatus of the first aspect, wherein the seat pad has a substantially U-shaped slit formed in a side pad portion of the seat pad at a position opposing the air bag accommodating concave portion. The substantially U-shaped slit includes a base portion and two parallel leg portions forming a substantially U-shape, and the leg portions extends from the base portion toward the rear of the vehicle.
In the seat structure having a side impact air bag apparatus according to the second aspect of the present invention, an air bag cover is formed by the portion surrounded by the generally U-shaped slit formed in the side pad portion of the seat pad. Also, since the lid portion of the air bag case can be omitted, the ease of assembly can be enhanced further.
A third aspect of the present invention is a seat structure having a side impact air bag apparatus. The seat structure includes a seat back frame which has side frames each provided at a corresponding widthwise direction side of a seat. An inflator mounting opening is formed in one of the side frames which opposes a vehicle door so as to allow an inflator and an inflator accommodating portion of the side impact air bag apparatus to pass therethrough. A seat pad is provided for covering the seat back frame, and a seat surface layer is provided for covering the seat pad. The seat surface layer covers the inflator mounting opening, the side impact air bag apparatus and the seat pad.
In the seat structure having a side impact air bag apparatus according to the third aspect of the present invention, the inflator and the inflator accommodating portion are fitted into the inflator mounting opening. Accordingly, the interior room space of the vehicle can be increased. Moreover, the inflator can be supported with increased rigidity.